1. Field of the Invention
The present invention relates to a tampon and, in particular, to a tampon having a plurality of segments of absorbent material.
2. Description of the Prior Art
Tampons constructed of a plurality of segments of absorbent material are known. For example, tampons having a plurality of absorbent layers spaced along a thread are described in U.S. Pat. Nos. 3,965,905 and 5,542,914 as having increased absorption capacity due to increased surface area. U.S. Pat. No. 3,965,905 describes the spacing between adjacent absorbent layers to be such that they do not contact one another so as to enhance expansion of the segmented tampon into irregular shapes. The individual segments of the tampons shown in these patents bloom (expand when saturated with fluid) substantially together.
U.S. Patent Re. 27,677 discloses a tampon having an interior layer and an exterior layer of absorbent material with an intermediate layer of moisture impervious material that has an array of perforations. The perforations are described as directing rapid and/or initial flow of menstrual fluid to the interior layer. However, the perforations, being located between the two layers, will allow fluid to flow to each of the layers simultaneously. The net result is that the interior and exterior layers bloom substantially together.
U.S. Pat. No. 4,335,720 discloses a tampon that prevents strikeover or premature swelling of the insert end of the tampon that causes fluid flow along the outside thereof. The tampon is formed of an interior layer and an exterior layer of absorbent material separated by a layer of impervious material. A hollow core with radial slots is formed within the interior layer. Both the hollow core and the radial slots open to the insertion end of the tampon. Fluid at the insertion end is directed by way of the open end of the core and the radial slots to the interior core for absorption by the interior layer. This tends to retard strikeover or premature swelling of the insert end.
It is an object of the present invention to provide a tampon that has a plurality of pledget segments that absorb and expand independent of one another.
It is another object of the present invention to provide such a tampon that has a plurality of pledget segments with each segment having motion flexibility that is independent of an adjacent segment, thereby providing user comfort.
It is still another object of the present invention to provide such a tampon where the plurality of pledget segments are contained in a coverstock bag, thereby providing enhanced user comfort.
It is a further object of the present invention to provide such a tampon where the semipermeable layer of the segment at the insertion end of the tampon is extended to surround the plurality of pledget segments and form a cover.
It is still a further object of the present invention to provide such a tampon where the pledget segment at the insertion end of the tampon is fixed to a withdrawal cord, while the remaining plurality of pledget segments are not fixed to the withdrawal cord and are able to float along the cord.
These and other objects of the present invention are achieved by a tampon that has a plurality of segments positioned along an axis, such as, a withdrawal cord, so as to permit expansion movement of any segment during absorption independent of other segments. Each of the segments includes one or more absorbent layers and one or more layers of semipermeable material that form the bottommost layer of the segment. The bottom, or final segment, at the withdrawal end of the pledget, may not have the semipermeable material. The layers of semipermeable material act as absorption barriers that delay substantial fluid absorption by the absorbent layers of a next segment until the absorbent layers of a preceding segment have absorbed fluid and expanded substantially. This allows each segment to absorb and expand independently from the other segments.
To further enhance user comfort, the plurality of pledget segments may be contained in a coverstock bag that either totally encases the pledget segments or a coverstock that is open at the insertion end of the tampon.